ENVIRONMENTAL CORRELATES OF GEOGRAPHICAL DISTRIBUTION OF TERRESTRIAL VERTEBRATES IN ISRAEL

ABSTRACT

Species richness in Israel was studied by correlating the number of species of mammals, birds, and reptiles in 30 × 30 km squares with several environmental factors. The most diverse areas in Israel (in terms of number of species) were transition zones between the Mediterranean, Irano-Turanian, and Saharo-Arabian regions. For mammals and birds, the factors best correlated with species richness were, in decreasing order: number of isohyets per square, mean annual precipitation, and number of plant communities. These factors are highly correlated with latitude, hence a very high correlation exists between latitude and species richness. For reptiles, species richness was significantly correlated with the number of soil types, followed by mean annual evaporation and mean August temperature. Most environmental factors examined were highly correlated among themselves, hence no definite conclusion as to the most important factor can be drawn. For terrestrial vertebrates within Israel, species richness declines from north to south, and its variation is predominantly explained by abiotic and vegetation factors.